Storms, hail in Colorado, Arizona ablaze

A pedestrian runs for safety as a hail storm hits downtown Colorado Springs, Colo., May 21. Photo: AP/Wide World Photos

More spring thunderstorms delivered hail and triggered tornado sirens in Colorado, May 22, a day after six tornadoes touched down east of Denver.

No significant damage was reported from the twisters, and the latest round of storms wasn’t expected to be as extreme or as widespread as that seen earlier in May.

Three of the tornadoes touched down in and around Aurora, while the others hit north and east of Denver, including one about 13 miles from Denver International Airport.

Hail covered roads and grass in some parts of the Denver and Colorado Springs areas, with snow plows called out to clear runways and the access road to the airport. Golf ball-sized hail piled up 4 inches near Strasburg on the plains 40 miles east of Denver, the National Weather Service said.

The storms temporarily grounded flights at the airport and forced 40 flights to be diverted May 21. Frontier Airlines canceled some flights after six of its planes were damaged by hail. It is waiving change fees for passengers who needed to rebook their flights through May 22.

A microburst is blamed for ripping a section of metal sheeting off the roof of Castle Rock’s town pool.

Lower-level winds weren’t forecast to be as strong May 22, which means any tornadoes that form will likely be more short-lived, National Weather Service meteorologist Kari Bowen said.

The chance for afternoon thunderstorms to develop was to continue until Memorial Day weekend. Besides the risk of tornadoes, heavy rain could also cause flooding if the cells hit some of the areas burned by recent wildfires.

Hundreds of firefighters worked May 22 to hold off a wildfire that started in a scenic canyon in northern Arizona, prompting residents of outlying areas of Flagstaff to prepare to flee and blanketing the city in smoke.

The human-caused Slide Fire started May 20 and had burned 7.5 square miles in and around Oak Creek Canyon, a scenic recreation area along a highway between Sedona and Flagstaff.

Fire incident commander Tony Sciacca said the fire was 3 to 3 1/2 miles away from the residential areas of Forest Highlands and Kachina Village, where 3,200 residents remained under pre-evacuation warnings. Firefighters had no containment on the blaze, but were pleased that it only grew a couple hundred acres overnight after increasing tenfold in size the previous day.

A primary focus of firefighting efforts will be to pinch off the fire where it has reached the top of the canyon’s northeast corner to keep it from burning northward toward the residential areas, said Dick Fleishman, a spokesman for fire managers.

Mr. Sciacca said 500 firefighters were assigned to the fire May 22, with an additional 200 personnel expected later that day as more crews and engines arrive. (Compiled from Associated Press reports.)